Filial Piety
by Gigabomb
Summary: Vexen, Riku's Replica, prior to and during Chain of Memories. In which an experiment is unexpectedly successful and Vexen has absolutely no idea what to do with the results.


Author's Note: Thanks goes out to kytha for the rather weird idea of Vexen as a parental figure for the Riku Replica, and to silvestris because the Vexen & Marluxia scene in this rips off mercilessly from her Marluxia/Vexen fic on Y!Gallery, though without the porn

It was partially from desperation, partially from curiosity that trial number ninety-seven was conducted using material from the keyblade bearer known as Riku. All prior trials had failed miserably, the cloned hearts shuddering to life only to collapse in on themselves within seconds. And those were the more successful tests. Most of them never made even that much progress, fading to wisps of light before coming properly into existence.

It was not because of the Superior that Vexen sought so diligently a conclusion to this experiment. Xemnas was aware of what Vexen was doing, in a vague, uninterested sort of way, but the leading member of Ansem the Wise's former apprentices had lost the vast majority of his scientific interest along with his heart, and Vexen doubted the other Nobody had bothered wading through Vexen's reports to the extent that the Superior actually had a grasp of what was going on in the laboratory of the Castle That Never Was. So no, it wasn't the leader of the Organization Vexen had in mind when he finally decided to go through with trial number ninety-seven. He just didn't like the thought that the previous ninety-six trials had been a waste of his time.

Even so, ninety-seven was definitely the final test. There were only so many failures Vexen was willing to go through before moving on to more promising research.

A few strands of the keyblade bearer's hair were enough. Vexen didn't foster much in the way of hopes—hoping was a frivolous activity wasting energy best spent elsewhere—but… All previous material had been taken from ordinary people, with ordinary hearts. It made sense that a clone of someone with a heart strong enough to wield a keyblade might endure, when others did not.

The heart coalesced in the oversized test tube made specifically for this particular experiment, coming together piece by piece as if gathering substance from the air around it. It beat once, twice. Thrice. Vexen smiled.

----

The body formed some hours afterward, while Vexen was still deciding the best way to go about examining it. Unfortunately there was no chance of creating another clone, as all the viable material had been expanded. Which meant he had to be careful.

He hadn't expected to find the naked, unconscious body of a fifteen year old boy at the bottom of the test tube, curled up in a fetal position with its legs pressing against its chest. But then, there was no precedent for this. None of the other hearts had survived long enough to finish their growth. Or something. It wasn't like Vexen had enough evidence on which to base a reliable hypothesis.

He stared at the sleeping figure, briefly considered the viability of extracting the heart for further study, then immediately discarded the possibility. The only reliable way to remove a heart from a living creature was with a heartless, and the last thing Vexen wanted was to have his new test subject's heart consumed. Then the entire experiment really would be a waste.

In the end, he had opened up the hatch on the tube's side and summoned some Dusks to lay the replica onto the surface of one of his lab tables. As an afterthought, taking the temperature of his laboratory and the replica's unclothed state into account, he had then ordered another Dusk to find a blanket. It would be unfortunate if he lost his first success in weeks to something pedestrian like pneumonia.

----

He hadn't reported his experiment's conclusion to Xemnas. A success it had been, undoubtedly, but not one that would particularly further the Organization's cause. Whether he could create an artificial heart or not was unimportant. The question was if he could transplant such a heart to a Nobody, and the answer to that was a resounding no. Hearts only sat easily in their original vessels. The heart of another would reject a Nobody's being, perhaps to fatal effect.

Xehanort had always been extremely focused in his endeavors, but Xemnas could be unsettling in his single-mindedness. He didn't care about Vexen's pet projects, and would be irritated if Vexen used up the weekly meeting period to speak about what the Superior believed to be an irrelevant topic.

The replica didn't awaken for two days. Vexen wasn't even in his laboratory when the keyblade bearer's clone regained consciousness, having taken a short break to avail himself of some lunch. He had opened up a darkness rift to his laboratory, onion and cheese sandwich (with mustard) in one hand and a cup of coffee in the other, to find the replica with its eyes open and wide, the blanket wrapped around its shoulders as it sat with its legs dangling off the edge of the table. The eyes widened further as it watched Vexen enter, staring with no self-consciousness to speak of.

Vexen stared back, his coffee (cream, no sugar) steaming in his grasp. What followed might have been labeled an uncomfortable silence under other circumstances, if either of them had been human, or even if Vexen had cared. However, they weren't and he didn't, so the visual examination that took up the next few minutes was accompanied by no apparent awkwardness.

The replica spoke first. It had to clear its throat twice to wet its mouth sufficiently to allow speech, and the words still came out hesitant, as if it wasn't quite sure yet how to use its tongue to best effect. "Who are you?"

A list of possible responses briefly ran through Vexen's mind, 'I am your creator' and 'you may call me master' appearing near the top before quickly being crossed out—proud as he was of his accomplishment, he possessed neither Xemnas's capacity for theatrics nor Marluxia's delusions of grandeur and had no fondness for either—until finally deciding on, "I am Vexen."

The replica blinked. Once. "Oh." It then lowered its gaze slightly. It took Vexen a moment to realize that the replica's eyes were focused on his right hand. Or rather, what his right hand held in its grip. "That smells good. What is it?"

Trying to explain something like a sandwich to a being with no practical experience concerning absolutely anything to speak of would be an exercise in futility, so Vexen dispensed with explanations altogether and just walked over to the lab table where the replica was sitting and held out the sandwich for its inspection. The replica tilted its head as it examined what had been intended to be Vexen's lunch, blinked again, then took it from Vexen's hand, the blanket falling from one shoulder to puddle in its lap. It sniffed at the onions several times, then stared at Vexen again. "Um…"

Silently thanking years of writing up lab reports for the remedial classes he taught back at Radiant Garden, partly for gracing him with a increased supply of patience for the young in addition to a skill for simplifying procedures down to their most basic steps, Vexen said, "Bring it to your mouth, tear off a piece with your teeth, chew twenty times, then swallow."

The replica did so. Further instruction proved unnecessary after the first bite (though it did fail to chew the necessary number of times), its hands almost convulsing around the sandwich as its taste buds activated for the first time. The sandwich was gone in approximately two and a half minutes, leaving hints of its existence behind only in the crumbs scattered on the laboratory's linoleum floor and the mustard smeared around the replica's mouth. It was still licking its fingers as it shifted its focus to Vexen's left hand. "Um…"

It turned out that Riku's palate, or at least the palate of his clone, was not especially adapted to coffee (cream, no sugar). Or perhaps it was just too hot. He might have, Vexen supposed, waited a few minutes for it to cool. He absentmindedly summoned a Dusk to clean up the mess (the replica started at the lesser Nobody's appearance, but it seemed to calm as it registered Vexen's indifference to the newcomer) as he walked over to the sink with the now-empty coffee cup (fortunately it hadn't broken from the fall) to fill it with water with which the replica could rinse out its mouth.

It took him a few minutes to convince the replica that the water lacked both the coffee's temperature and its (admittedly) bitter taste, but eventually it overcame its apprehension.

Vexen observed the replica empty the cup clinically, the blanket slipping from its body entirely to end up in a heap on the floor. Interesting, how it still retained the memory of speech, but not of modesty. However, the cold still presented a problem. He would have to acquire it some clothes.

----

Even a set of Zexion's robes proved too large for the replica, the sleeves falling past its fingertips and the hem brushing the floor, but for the time being Vexen deemed them sufficient. Figuring out its living arrangements turned out to be a slightly more difficult, though hardly insurmountable, obstacle. The back rooms to his laboratory, complete with a small bathroom (which, fortunately if somewhat oddly the replica also recalled how to use), was enough for its accommodations after several Dusks brought down the sofa from Vexen's private rooms.

Ordering a separate Dusk to bring food from the kitchen twice a day at regular intervals provided for the replica's nourishment. It was not especially choosy, as long as the Dusk remembered coffee was on the list of banned goods and that it liked its fish charbroiled. The replica had a very high capacity for spicy foods, keeping down Number Eight's by-now infamous pepper sauce that Axel kept in the fridge with no visible trouble. Its favorite meals were chili with an extra dollop of sour cream and the meat spaghetti Xaldin made when it was his turn to cook, preferably with a popsicle for dessert. It didn't particularly care what flavor, though Vexen did note it possessed an odd affinity for sea salt. Vexen didn't find out until a few weeks after the replica's creation that the Dusk in charge of the replica's meal plan had been stealing the popsicles from Demyx's private stash, and might not have even realized then if he hadn't overheard the Melodious Nocture complaining about it to Xigbar one day after the weekly meeting period was over. Neither did he particularly care. Number Nine's existence concerned him not at all.

The biggest problem that plagued the replica's care was boredom, as it had literally nothing with which to occupy itself. Unlike how most of the Organization members might have acted under the same circumstances, it did not go out of its way to annoy Vexen in order to provide itself with some entertainment. However, the replica did make a habit of watching Vexen while he worked, and while it might have been worse, as the replica shifted little and said less, having the clone's green eyes constantly burrowing into his back did prove to be somewhat distracting.

A solution presented itself one day when Vexen walked into his laboratory's personal library where he kept all the books pertaining to his work to find the replica sitting cross-legged on the floor, its robe's hem tucked around its feet, as it thumbed through one of Vexen's illustrated chemistry texts. It startled slightly as it noticed Vexen's presence in the doorway, a distinctly guilty look crossing its face, before taking note of Vexen's lack of expression and letting its shoulders relax. "Hello."

"What are you doing?"

The replica bit its lower lip, a habit, Vexen knew, it couldn't have picked up from him. The replica's heart and body were exact copies of the original's, but its mind had started out a clean state. But still, it spoke, it ate, and it apparently bit its lower lip for no good reason. There was such thing as muscle memory, of course, but that didn't account for everything.

Memory had to come in some way from the heart, then. Not all of it, of course, as Vexen still remembered the vast majority of his time as Even and he had lost his heart along with the rest of Ansem's former apprentices. Not even most of it. But some.

It might make for an interesting experiment someday. But not now. Having only one subject to work with made for poor study. No baseline at which to start resulted in unreliable conclusions. Later, then.

The replica still hadn't replied, so Vexen repeated his inquiry. "What are you doing?"

The replica ducked its head. Then it did something unexpected. It _blushed_, the reddening of its cheeks just barely visible through its bangs. The mumble that followed was unintelligible.

Vexen frowned. "What?"

"I…" Its eyes flashed in what might have been interpreted as defiance if Vexen hadn't recognized the look as one his Other had occasionally worn back at Radiant Garden. The buckling of pride, and the subsequent attempt to hold onto what little endured. "I was looking at the pictures. I can't remember… I don't know what the symbols mean."

Hm. Apparently memory of literacy was not something the heart contained. That is, if the original had known how to read at all.

Vexen recalled teaching how to read to be a tiresome, time-consuming process, but there were many books here and many more in the main library of the Castle That Never Was, and keeping the replica occupied and out of Vexen's way while he was working might prove worth the effort.

Still, considering that most of the texts in his laboratory were intended for a very specific and very educated audience, they might prove too difficult for a beginner. And there were some children's books in the main library, if Vexen was remembering correctly, some mementos of a mission Axel had been assigned several months ago. There had been more than few resigned sighs at the Flurry of the Dancing Flame's choice of souvenir, but the children's books remained.

It was the work of a moment to send a Dusk to retrieve the books, the work of another moment for the Dusk to return, what passed for its arms wrapped around a stack of hard covers. Vexen took the chemistry text from the replica's hand and returned it to the shelf. Then he turned around. "Come."

They relocated to what served for the clone's bedroom, the sofa that acted as the replica's bed sitting in the corner, the blanket folded neatly (likely by a Dusk) and laid over the arm of the sofa closest to the wall. The pillow was no where in evidence. Vexen sat down—the replica following suit—and pulled one of the books from the stack the Dusk had placed on the small side table next to the sofa.

He opened the book to the first page. The replica leaned over into what would have been Vexen's personal space, had the replica been anything but what it was. However, as things were, having the top of the replica's head less than six inches from his chin barely registered at all. "Do you see this letter here? This is a 'c'…"

----

The replica knew what it was, the details behind its conception. It had asked in the first days of its existence, and Vexen had never seen any reason to lie to it. However, it only became truly curious about its original once the unfamiliarity of its current surroundings faded, and it began to grow used to the laboratory.

Most of the questions Vexen was incapable of answering.

"What were my original's parents like?"

"I don't know. Hand me the beaker to your left. No, not that one, the other beaker, the one with yellow specks in it."

"What sports did my original play?"

Vexen was beginning to sincerely regret some of the books he had procured for the replica's use. The instruction manual on the mechanics of blitzball in particular would forever be imbedded in his mind as an object of intense loathing. "I have no idea. Pass me the tongs."

"What-"

"If you are going to continue your line of inquiry, you have to move. You're in the way."

The replica moved. But it didn't stop asking questions.

Eventually it moved beyond trivialities, once it realized that Vexen had no details about its original's life back at the Destiny Islands. "Why didn't my heart disappear like the others?"

Vexen absently took a sip of his cup of coffee as he flipped the page of the newest academic journal Lexaeus had picked up during his latest assignment in Ivalice. It was supposedly a periodical intended for alchemists, but fortunately its roots were much closer to biochemistry than what Vexen considered to be true alchemy, a much less credible branch of science. He really wasn't all that fond of coffee, but it was the only beverage he could be assured that the replica wouldn't sneak sips of when he wasn't looking. Not that it could have acquired any communicable diseases in his laboratory, but who knew what sort of illnesses the original might have had? "Your original was a keyblade bearer, and thus possessed a very strong heart. Considering the adverse conditions under which you were created, it isn't surprising your predecessors ceased to exist so quickly."

The replica's brow furrowed. "What is a keyblade?"

That explanation had taken almost an hour. Soon afterwards Vexen had been forced to go on a mission to some backwards world with an inordinate amount of musical instruments, a mission that could have arguably been passed to one of the lower ranked Nobodies, but unfortunately some scientific expertise was needed in order to collect heart samples. Vexen returned to his laboratory five days later, the sound of clashing classical melodies and jazz tunes ringing in his ears and a migraine threatening, to find the replica in the largest of the back rooms of the laboratory, sitting cross-legged on the floor as had become his preferred reading position, a book Vexen didn't recognize spread open on his lap.

The replica looked up as Vexen entered, its eyes widening and its lips curling upwards in what appeared to be an unconscious reaction, jumping to its feet as Vexen strode across the floor. "Vexen!"

Vexen glanced at the cover of the book now dangling from the replica's right hand. The title read _A Beginner's Guide to Long Sword Fighting_. His habitual frown deepened. "That is an interesting choice." It wasn't a book that would be found in the Castle That Never Was, none of its occupants having the long sword as their weapon of choice, but Vexen had given the replica a short lesson on opening darkness rifts shortly after its creation with strict instructions never to go anywhere else within the castle. The original had had enough darkness within him that Vexen didn't fear the replica being consumed by the heartless or getting lost in the dark, and it freed him up from having to order Dusks to attend to the clone during its every waking moment. Likely it had found the book during one of its world excursions.

The replica's eyes followed Vexen's line of sight to the book in its hand. Its cheeks reddened. "I… I was just remembering what you said about keyblades. I thought I might summon one. I haven't managed it yet, but I figured that when I finally did, it might be good to know how to properly use a sword."

Vexen didn't know whether to be obscurely pleased that it had acquired the good sense to do thorough research on a new subject of interest, or annoyed that the replica had chosen to study swordplay, of all things. "It is not certain that because your original could use a keyblade you can wield one as well."

The replica's eyes narrowed. "What do you mean? You said that the power to use a keyblade is in the heart. We have the same heart. Why could he use one when I could not?"

"Conventionally, there is only one keyblade master, one who uses the power of light. The only reason Riku was able to bear a keyblade is because he utilized the power of darkness. Riku was recently entombed in the realm of darkness, which I suppose makes it a possibility that you could take possession of his keyblade, but the course Riku choose to gain his keyblade is one you are not likely to follow."

The replica scowled. "We have the same heart. I was created after my original started down the path of darkness. If he can wield a keyblade, so can I. Just watch me."

"Perhaps." Vexen returned to his laboratory. He had left more than one experiment on hold to go on his mission and was far behind schedule. He didn't have time to watch the keyblade bearer's clone toy with forces it didn't understand.

----

The creation of Castle Oblivion had been in the works for over a month, but it wasn't until the day after the replica made its plans of wielding a keyblade plain that the reassignments to the new base of operations were announced. Vexen hadn't expected to be on the list, but he supposed he really shouldn't have been surprised. Someone with some scientific education was needed for the investigations into memory, and out of the original six he was the only one who had really kept up on his studies. While he had briefly considered the possibility of being placed in charge of the Oblivion project, considering how much time he spent on research it wasn't really a viable option.

Still, when thinking of who would be the Superior of Castle Oblivion, he had expected Zexion, who had been in Xemnas's confidences ever since Radiant Garden, or Lexaeus, perhaps, who at least had the good sense to let the people who knew what they were doing work unmolested. Marluxia, with his relative inexperience and complete ignorance of anything at all technical, was the last person Vexen expected to take command. The last person Vexen wanted in command. The Nobody was arrogant, overbearing, sadistic, an unrepentant egotist, and always smelled as if he had just walked through a field of rotting roses, which gave Vexen a headache. And now Vexen had to _report _to him…

Vexen wondered what he had done recently to anger the Superior so much as to deserve this. Surely missing out on the last two weekly meeting periods wasn't as important as all that.

It was simple to relocate the replica along with the rest of his research materials to the basement laboratory in Castle Oblivion. The replica, in fact, provided the most in the way of assistance for transporting most of his equipment, as for some reason Xemnas was insistent on keeping all the lower ranked Nobodies out of Oblivion, to the point of forbidding Vexen from using any of them to help him move. The look in his eye had kept Vexen from raising too much protest.

Most of Vexen's books had to be left behind, and the space allotted for his research was even smaller than it had been back in the Castle That Never Was. As a result, there was very little for the replica to do, hidden from the rest of the Organization as it was, and though by that point it had acquired through way of observation enough scientific know-how to aid Vexen in the least complicated phases of his experiments, it didn't take long before it grew weary of Oblivion's basement and started staying away for longer and longer periods of time. Vexen didn't particularly care. He had never gotten around to studying the unique characteristics of the replica's artificial heart and was even busier now, so while it was around it provided more in the way of a nuisance than a point of interest.

The replica was away on one of its sojourns, this time to the world it had designated as 'the place with the nice beaches and the six-legged blue dog thing,' when Marluxia first came down to the basement on one of the younger Nobody's impromptu tours of his new domain. Vexen was in the middle of distilling the essence of two separate hearts to see if they would bind together in an attempt to complete themselves—something he already knew to be a futile exercise, but one never knew—when he felt the distinct absence behind him that signaled an opening of a darkness rift. Even before his nose caught hold of the scent of dying flowers he knew who it was. Zexion and Lexaeus always gave him the courtesy of knocking before entering the laboratory, and Larxene and Axel had next to no interest in the workings of the lower levels.

Vexen carefully set down the beaker which contained one of the distilled hearts before turning to face his new… superior. "Marluxia."

Number Eleven's smile, the grin of a man utterly confident of his place in things, grated like sharpened nails on Vexen's nerves. "Vexen. Hard at work, I see?"

Vexen nodded tightly. He resisted the urge to clench one of his hands into a fist. Marluxia had been there less than two minutes and already he had grown tired of the Graceful Assassin's presence. That was not a good sign. Not if he had to report to the other Nobody on a regular basis. "Did you want something?"

Marluxia walked slowly over to one of the counters where another of Vexen's experiments was simmering, looking down with feigned interest at the contents of the glass sitting over the burner. "Just thought I would see what my resident scientist was occupying his time with. I should have come earlier, I know, but you know how time-consuming running a castle can be." The Graceful Assassin followed his insincere apology with a smile that made it clear that he knew Vexen had no idea what entailed commanding a castle full of Nobodies. As if Vexen would ever want to. If Zexion or Lexaeus had been placed in charge he would have never given the hierarchy of Oblivion a second thought, but Marluxia… Marluxia…

So consumed was he with not giving into the impulse of slapping Number Eleven's hand away as it rubbed along the edge of the simmering glass that he almost didn't hear the Graceful Assassin's following words. "… did want to ask you about something. I was going through the Superior's files on matters of the heart before the Oblivion project began, and found some interesting reports filed by you on the prospect of creating artificial hearts. However, the account taper off a few weeks after the initial hypothesis was filed. Whatever did come of that experiment, Vexen?"

If it had been Xemnas asking, Vexen wouldn't have hesitated for more than a minute or two before giving the Superior his final conclusions. Xemnas might have been irritated that Vexen had waited so long, but the project had mattered so little to Xemnas that it wouldn't have been a reason for contention between them. But the Nobody in front of him wasn't Xemnas, and Marluxia had a talent for twisting words around to suit his own purposes. Not wanting to bother the Superior with trivialities on Marluxia's tongue would be synonymous with treason, and higher number or not, Number Eleven had wormed his way into Xemnas's favor and been given command of Castle Oblivion, and chances were that even if Vexen did get a chance to speak on his own defense, it wouldn't matter in the least.

So Vexen did what he had long ago discovered to be the best policy when dealing with the Graceful Assassin. He set his face into its most neutral lines, and lied. "All the artificial hearts I attempted to create collapsed in on themselves before completion. I gave up the experiment as a dead end."

"Mm. Really? That's too bad."

It was an effort to restrain his face from shifting into a grimace. That was not the response Vexen wanted. Marluxia was a good enough liar himself to perhaps spot a blatant fabrication if he was looking for it, and Marluxia was almost always looking for it.

Vexen felt the hair prickle on the back of his neck as Marluxia strode over to where he was standing, the pleasant, self-satisfied smile never leaving his lips for a moment. It was less than six inches from Vexen's ear that Marluxia breathed. "It really is too bad, Number Four. Even if the Superior had little interest in it, I believe the experiment held quite a bit of potential." The Graceful Assassin leisurely wound two of his fingers in one of Vexen's forelocks, tugging slightly, making Vexen feel the pull on his scalp.

The keyblade bearer's clone was fond of Vexen's hair, talking animatedly sometimes about how it planned to grow its own hair to be just as long, asking if it could comb his hair out on the rare occasions it grew tangled. Vexen had bore it without any particular irritation, letting the replica do as it wished with the comb it had found somewhere as he read one of the books on the sofa that at night served as its bed. Just as when it had sat beside him as he taught it how to read, its close proximity rarely registered, even the one time it had patterned his hair in an intricate braid it had read about in a book concerning horses while he was distracted by an unusually detailed proof explaining the process of turning lead into gold. He hadn't even noticed until the black bow had been tied at the end.

But Marluxia didn't have the Riku replica's innocent intentions. The tugging soon grew painful, making Vexen grit his teeth for a number of reasons, Marluxia moving closer all the while until Vexen could feel the heat radiating off the Graceful Assassin's body. "Quite a bit of potential, indeed. In fact, I think that if you had used subjects with stronger hearts, you might very well have succeeded. You see, Vexen, I think we will be having some very interesting guests soon. When they arrive, I want you to see what you can do with some truly powerful hearts. Alright?"

It wasn't a question of assent, but of comprehension. As if Vexen was a stupid dog that might need to have its instructions repeated before it could grasp what was being asked of it.

Marluxia was close, so close. If only Vexen dared… "I understand."

Marluxia smiled, one last time. "I'm glad. Until then, Number Four." He left as he had entered, and only then did Vexen allow his hands to clench.

"I didn't like him."

Vexen twisted around so quickly he nearly lost his balance. In the doorway of the bedroom he and the keyblade bearer's clone now shared stood the replica, the now ragged hem of its robe, dusted with wet sand at the moment, brushing the tops of its equally dirty bare feet, the sleeves reaching the last joint of its middle fingers. The replica had grown since its creation. Just as if it was a real person after all.

But that wasn't the matter at present. "How long have you been standing there?" Had Marluxia possibly… but no. The Graceful Assassin's gaze would have shifted, at least, had he noticed the replica.

"I just came out when the pink-haired man left. I heard everything, though." It didn't seem pleased to have been present for the conversation. "I really, really didn't like him. He was a complete jackass."

"Language," Vexen corrected automatically. It had a better vocabulary than that. It certainly read enough.

The replica scowled. "Well, he was. Even if he is your boss, he shouldn't have treated you like that. Shouldn't have touched you. When he did that, I…"

The replica was shaking, Vexen noted with some surprise. With anger, of all things. "When he did that, I wanted to kill him. If he does it again, I will."

Vexen snorted. "Don't be ridiculous. Marluxia is one of the strongest fighters in the Organization. You wouldn't stand a chance against him."

"Not now." Implying, of course, that it would be strong enough to destroy Marluxia later. The idea was nearly laughable, would have been, had Vexen not wished for that outcome as well. He fostered nothing in the way of hopes—hoping was a useless, worse than useless way to spend one's time—but… but there was nothing.

"Not ever," Vexen countered, harshly. If this discussion had been taking place with anyone else, he would have chosen that moment to stalk into his room to get some distance, but the bedroom was as much the replica's domain as it was his, so instead he turned in the opposite direction and left the laboratory entirely.

He didn't return for some hours, spent the time in the basement kitchen watching Zexion fry squid at the stove and Lexaeus leaf through a mystery novel at the table, before growing sick of the company, however amiable. The replica was asleep on the bedroom sofa when he returned, and he didn't awaken it, just slipped out his robe and went to bed himself.

Vexen regained consciousness to find the replica was no longer there. He didn't worry himself about it, just finished the heart binding trial of the day before to the expected unsatisfactory results and started cleaning up the leftover materials. He had just put the last stained glass in the sink when the replica returned, opening up the darkness rift in the bedroom as the usual precaution to avoid running into anyone who might be in the laboratory. Vexen didn't even bother turning around to acknowledge its presence, just started rinsing out the last glass and saying curtly, "I hope that you at least had to courtesy to bring back breakfast-"

"Soon."

Vexen turned his head, annoyed at the interruption. "What are you taking ab…" He trailed off at the sight of the curved, edged blade in the replica's hand. The heartless symbol on its chest, just visible above the neckline of its second-hand robe. The red, blue-fingered gloves. The blue, heavy-treaded boots. The black that ran up its neck, just stopping at the line of its jaw. The angry red line that ran across its brow, dripping blood down its face.

The replica grinned at his look of astonishment, triumph lighting its eyes, taking no notice of its injury, however it had been gained. "Soon, I will be strong enough to destroy Marluxia. I will be able to make it so he never touches you again. Not yet. But _soon_."

----

The keyblade master, along with his two companions, arrived a few days after that. Riku made an appearance hours later. Throughout it all, the replica trained. As both keyblade bearers fought their way through Castle Oblivion, Vexen made false reports to Marluxia about his progress on the artificial heart experiment, even making a show of fighting Riku and pronouncing it to be data collection to further along the project. Laughable, really. Xemnas would have seen right through the deception—what possible good could observing the original do when all that was needed to create a copy was a DNA sample?—but Marluxia accepted Vexen's reports without a second look.

It was through the basement's crystal ball that the replica watched the keyblade bearers' trek throughout the castle. Watched Sora's fight with Axel. Watched it all, its green eyes narrowed in thought.

On the second day, it approached Vexen. "Marluxia is stronger than Axel."

Vexen nodded.

"The light keyblade's bearer was barely able to keep up with Number Eight. And Sora is as strong as Riku."

Vexen nodded again, and took a sip of his coffee. It wasn't as good as the coffee at the Castle That Never Was, but Zexion didn't have Luxord's impeccable timing and often let the beans stew too long.

The replica bit its lower lip in thought. It had discarded Zexion's appropriated robe after it had figured out how to garb itself in darkness, claiming the too-long sleeves made it difficult to keep its grip on its keyblade. Vexen didn't understand why it thought it needed to provide an explanation. It wasn't as if he cared. "Does that mean… does that mean that if I'm to destroy Marluxia someday, I need to be stronger than them? Stronger than Sora and Riku?"

Vexen didn't know why the replica held onto that ambition. Keyblade or not, it had become a bearer less than a week ago. No matter if it had figured out how to control the darkness, seven days of intense study could not compare to Marluxia's years of wielding his own unique powers. But he humored it, nonetheless. It was something to hope for. Who knew. One day, it might even succeed. "Yes. In order to hope to defeat Marluxia someday, you need to be stronger than your original." Much, much stronger, though that he did not vocalize.

The replica nodded thoughtfully. The next day, mere minutes before Vexen went to hand in yet another falsified report to Marluxia, the replica stopped him. "Vexen. When Marluxia asks you if I am ready, tell him… tell him yes."

If the plea hadn't been obvious in the replica's voice, if not its words, Vexen might have said no. As it was, he hesitated only a moment before nodding. "Very well."

It tried. Vexen would grant it that, at least. It tried, against Riku. And it failed. There were some things that couldn't be made up with shortcuts, and experience was one of them. Vexen hadn't really expected anything else.

The second time it made its attempt, this time against the light keyblade bearer, it faired little better than it had against its original. Marluxia watched its goings-on with palpable contempt. "Is _that _all a clone of Riku can do?"

Vexen remained silent. He didn't point out that lacking a true background in combat, it only made sense that the replica would falter when faced with experienced swordsmen. Marluxia wouldn't care to hear it.

The Graceful Assassin's exact sentiments on the subject were made clear when the replica returned, limping and with a bruise forming on its left cheekbone where Sora had clipped it with his keyblade's hilt. Even with the evidence of its failure stamped across its body, still it protested Number Eleven's assessment. "I can do it this time! I know I can!"

"It is obvious you cannot."

If that had been the end of it, Vexen would have thought it a good object lesson, sent the replica off somewhere to perfect its skills—the Land of Dragons, perhaps, they had veteran swordsmen there and plenty of Heartless on which it could hone its techniques—and gone back to his laboratory to finish one or two outstanding experiments. But by the glint that entered Marluxia's eyes as he looked upon Riku's copy, it was not the end. Not at all.

It took the flash of a piece of paper in Marluxia's hand for Vexen to know what was coming. "A card made by Namine. Yes. That will do nicely."

The replica frowned. Despite having watched its original and Sora over the past few days, it was obvious it still had no idea what Marluxia had in mind. "But it's just a card. What good is that?"

Next to Marluxia, Axel frowned. Number Eight's voice was flat as he replied, "That card contains Sora and Riku's memories of their home."

By the smirk that crossed Larxene's face on the other side of the room, she knew very well what Marluxia had planned. "This is your chance to get your hands on the real Riku's memories. All you need is that card and a little help from Namine. Maybe we'll get her to make you forget you're fake... Better yet, we could remake your heart so you can be just like the real Riku."

The replica's eyes widened. It took a step back. Then another. "H-hey… hold on! What do you mean, remake my heart?! The real Riku's a wimp who can't deal with the darkness inside him. What do I want with the heart of a loser?"

Larxene turned to Vexen, then, ignoring the replica's objections entirely. Her grin matched Marluxia's, empty of anything that might have once bound her to her Other. "Any objections, Vexen? Do you or don't you want to test Sora?"

Vexen had never cared about Sora. Didn't think that the light keyblade bearer was the key to getting back their hearts. But he knew what Larxene and Marluxia wanted to hear. The only words that would save his own life. And his creation's. "It must be done."

The face of the replica was stark with betrayal. "W-what? Vexen…" It searched his expression. Found nothing. What it said next came out in a whisper. "Vexen, how could you?"

The last words Vexen said to the replica were a lie. "Didn't I say I intended to make good use of you?" He had never said anything of the sort. Had never intended to do anything with the replica, really. But it had wanted to fight its original and Sora. Had wanted to become stronger. And all Marluxia had seen was failure.

It- _he_ had wanted to become stronger to kill Marluxia. So Marluxia could never touch Vexen again. But the replica had fought this time in Marluxia's name, and lost. And Marluxia didn't tolerate weakness. Vexen's creation had to become stronger, or die.

Vexen knew what Namine could do to someone's memories. By the time the witch was done, it was likely the replica would have no memory of Vexen, wouldn't even remember his creator's name. But… better to live a false life than none at all.

He left before Namine's card began its work, but the screams reached his ears, nonetheless.

----

_So... this is the end. Figures. But I'm not afraid. Good riddance to an artificial life. I never had a real heart. Even what I'm feeling now is probably fake._

_Which of my memories are real, and which are not? What I'm feeling now… are they just more fake memories, implanted by Namine? Of course they are. But still… Sora… he said that even if the memories are fake, even if **I** am fake, the feelings are real. So… who did I want to fight for? Who did I want to protect?_

_I guess… I guess I'll never know._

_**END**_


End file.
